Affiliations: [a] Department of Biomedical Engineering, I-Shou University, Jiaosu Village, Yanchao District, Kaohsiung City, Taiwan, R.O.C. | [b] Department of Electrical Engineering, I-Shou University, Dashu District, Kaohsiung City, Taiwan, R.O.C. | [c] Department of Medical Imaging and Radiological Sciences, College of Health Sciences, Kaohsiung Medical University, Kaohsiung City, Taiwan, R.O.C.
Correspondence:
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Corresponding author: Po-Chou Chen, Ph.D., Department of Biomedical Engineering, I-Shou University, address:
(82445) No. 8, Yida Rd., Jiaosu Village, Yanchao District, Kaohsiung City, Taiwan, R.O.C. Tel.: +886 7
6577711/Ext. 3448; Fax: +886 7 6577056; E-mail: pcchen@isu.edu.tw.
Abstract: BACKGROUND:Arterial embolism is a major cause of ischemic stroke. Currently, digital subtraction angiography (DSA) is the gold standard in clinical arterial embolization examinations. However, it is invasive and risky. OBJECTIVE:This study aims to longitudinally assess the progression of carotid artery embolism in middle cerebral artery occlusion animal model (MCAO) using magnetic resonance imaging (MRI) techniques. METHODS:Turbo spin echo (TSE), time of flight magnetic resonance angiography (TOF-MRA) and diffusion weighted magnetic resonance imaging (DWI) were used to evaluate the image characteristics of cerebral tissues at 1, 2, 3, 7, 14, 21 and 28 days after MCAO microsurgery on Sprague-Dawley (SD) rats. Quantitative analysis was performed and compared in MCAO hemisphere and contralateral normal hemisphere. Furthermore, pathologic section using triphenyl tetrazolium chloride (TTC) stain was performed as well. RESULTS:TOF-MRA showed carotid signal void in the embolism side, which is evidence of artery occlusion. The used MRI techniques showed that edema gradually dissipated within one week, but there was no significant change afterwards. The time-varying signal intensity of MRI techniques in MCAO hemisphere changed significantly, but there were no significant changes in contralateral normal hemisphere. Cerebral injury was also confirmed by analysis of pathology images. CONCLUSIONS:The MCAO animal model was successfully established on SD rats using the microsurgery to assess arterial embolization of intracranial tissue injury.
Keywords: Time of flight magnetic resonance angiography, diffusion weighted magnetic resonance imaging, apparent diffusion coefficient, Sprague-Dawley rat, middle cerebral artery occlusion animal model, ischemic stroke
